Keynote stops during slide show - RAM issue?

I do presentations about my trips to Auschwitz - a fee slides with info and then 300+ photos.

Yesterday I was doing my talk at a library and 75% of the way through a 300+ slide presentation, I got black screens.

I was using my Apple wireless keyboard to advance slides and it worked perfectly.

But at one point the next slide was black - nothing.

Then I pushed the arrow key a couple of time and a slide - maybe the next slide or two away showed up and then it happened again.

I had to quite Keynote and quickly switch to a pdf version to finish my talk.

Is it possible to go through slides too fast and the iPad chokes?

Is to possible for the iPad to run out of RAM?

It is a brand new 12.1 iPad Pro that is nearly empty (I know difference between storage and RAM btw).

Ideas?